This invention relates to a coated metallic article having a paint film formed by applying pigment-containing synthetic resin paints to the substrate and baking or curing the coating. More particularly, the invention is concerned with a coated article having two or three layers of paints different in pigment contents, and which takes the form of either a container for canning a drink, fruit, vegetable, or other food or a coated metallic sheet for fabrication into containers for general purposes.
Containers themselves or metallic sheets to be worked into containers are usually decorated by giving an under-coat of a paint containing a white pigment to the metallic substrate, printing the under-coat layer with ink of a desired color, and then finishing the printed surface with a top-coat of a protective varnish. The multilayer paint films formed by superposition of single layers of coating materials different in color and/or dissimilar in kind are well-known.
The term "single layer" as used herein means a layer formed by not only one coat but two or more coats of a paint, consisting of a synthetic resin as the vehicle solid and a given proportion of a pigment contained, and which looks homogeneous throughout as a single layer when cut crosswise and visually observed.
The decorative paint films on those metallic sheets are required to exhibit the desired degrees of saturation and lightness of color. For example, in case of the paint film that contains the white pigment and is often used as the under-coat, a paint prepared by mixing a white pigment in the maximum proportion permissible from the viewpoint of coating operation or of the resulting film with a synthetic resin as the vehicle solid of the paint is applied heavily in a thick layer where a high degree of lightness is required or lightly in a thin layer where lightness may be low, thus forming an under-coat layer of a desired lightness.